Source : Webster's Revised Unabridged Dictionary (1913)

Transformer \Trans*form"er\, n.

   {Multiple transformer}. (Elec.)
   (a) A transformer connected in multiple or in parallel with
       the primary circuit.
   (b) A transformer with more than one primary or more than one
       secondary coil.

   {Parallel transformer} (Elec.), a transformer connected in
      parallel.